This invention relates to suction catheters for aspiration of mucus and other fluids from the tracheobronchial passages, and particularly to catheters having improved tip structures which allow more efficient suctioning of the entrances to the bronchial tubes, and which reduce the likelihood of trauma during the suctioning procedure.
Traditionally, suction catheters have consisted of a flexible plastic tube having a beveled end, an end opening, and an opening spaced substantially back from the beveled end and passing through the top wall section, that is, the wall section which extends to form the tip of the beveled end. Such catheters have been relatively inefficient in some orientations in that air passing through the second opening reduces the suction available at the end opening. Moreover, the high degree of suction at the top opening when the end opening is occluded is apt to cause trauma to delicate tissues. See for example, the article entitled, "Pathogenesis and Prevention of Tracheobronchial Damage With Suction Procedures" appearing in the September, 1973 issue of CHEST (64 Chest 284 - 290).
Various catheter designs have been proposed, but these generally have a flat, rather than a beveled end. The lack of a beveled end makes such catheters more difficult to guide, particularly past the epiglottis into the trachea, and subsequently into the left mainstem bronchus, which is more difficult to reach than the right because of its sharper angle of bifurcation.
References indicating the state of the prior art include U.S. Pat. Nos. 3,319,628, 3,375,828, 3,407,817, 3,517,669, 3,590,820 and design U.S. Pat. No. 223,247.
It is therefore, an object of the invention to provide a more efficient and less traumatic catheter, which can be more easily directed into the desired bronchial passages.
Another object of the invention is to provide a suction catheter which will effectively aspirate thick bronchial mucus, without unduly traumatizing delicate tissues. Other objects and advantages of the invention will become apparent from the following discussion.